Pain, Postoperative, Caesarean Section
Conditions
Keywords
postoperative pain, infiltration analgesia, ropivacaine, Caesarean Section
Brief summary
Infiltration of a local anesthetic into the surgical wound is a simple method to strive to control postoperative pain after surgery. In the investigators institution, this method is used quite often. However, there is a controversy regarding the analgesic efficacy. Moreover, the cost of the single use elastomeric pump used with this procedure is clearly higher than the costs of other routinely used analgesic methods. According to the investigators observations, infiltration of a local anesthetic into the surgical wound after caesarean section seems to reduce the need for rescue analgesics. However, the scientific evidence of the efficacy of this technique is weak. The investigators decided to conduct a prospective, controlled, randomised, double blind trial on this topic. The hypothesis is that wound infiltration with local anesthetic will reduce postoperative pain and opioid consumption after caesarean section without major adverse effects.
Interventions
Postoperative wound infusion 2 ml/ h/ 48h
DRUGNaCl 0,9%
Postoperative wound infusion 2 ml/h/48h
Sponsors
North Karelia Central Hospital
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
FEMALE
Age
18 Years to 45 Years
Healthy volunteers
No
Inclusion criteria
* volunteer * age over 18 years * spinal anesthesia * ASA 1-2 * no allergy to used medications * no medications which have effect on pain perception
Exclusion criteria
* patient's refusal to participate * marked systemic disease
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| The Demand of Rescue Analgesics (Oxycodone) | 48 hours | The amount of oxycodone required 48 hours after operation. Oxycodone was administered when the strength of pain is over 3 on numeric rating scale (NRS) 0-10. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Strength of Pain on Numerical Rating Scale (NRS) | 48 hours, divided to five time intervals (0-6 h, 6-12 h, 12-24 h, 24-36 h and 36-48 h) | Intensity of pain was recorded on a numerical rating scale (0-10), where higher scores mean more severe pain, during rest and when moving, for five time intervals (0-6 h, 6-12 h, 12-24 h, 24-36 h and 36-48 h); for each time interval, the highest recorded pain score was taken into account. |
| Postoperative Nausea and Vomiting (PONV) | 48 hours | The numbers of patients with at least mild nausea at any time post-operatively. |
Countries
Finland
Participant flow
Pre-assignment details
Three patients were excluded after recruitment and randomisation, for the following reasons: For one patient, an emergency operation was needed before the scheduled operation time; for one patient, the hospital pharmacy was unable to provide the study drug in time, and for one patient, no study drug was initiated because of communication errors.
Participants by arm
| Arm | Count |
|---|---|
| Ropivacaine 0,75% Patients undergoing caesarean section under spinal anaesthesia
Ropivacaine 0,75%: Postoperative wound infusion; initial bolus of 10 ml, followed by an infusion of 2 ml/ h/ 48h | 33 |
| NaCl 0,9% Patients undergoing caesarean section under spinal anaesthesia
NaCl 0,9%: Postoperative wound infusion; initial bolus of 10 ml, followed by an infusion of 2 ml/h/48h | 34 |
| Total | 67 |
Baseline characteristics
| Characteristic | NaCl 0,9% | Total | Ropivacaine 0,75% |
|---|---|---|---|
| Age, Continuous | 30.9 years STANDARD_DEVIATION 5.7 | 30.5 years STANDARD_DEVIATION 5.7 | 30.1 years STANDARD_DEVIATION 5.7 |
| Dose of spinal bupivacaine, mg | 11.7 mg STANDARD_DEVIATION 0.8 | 11.8 mg STANDARD_DEVIATION 0.8 | 11.9 mg STANDARD_DEVIATION 0.8 |
| Height, cm | 162.9 cm STANDARD_DEVIATION 6.4 | 162.6 cm STANDARD_DEVIATION 6 | 162.4 cm STANDARD_DEVIATION 5.7 |
| Length of operation, min | 46.6 min STANDARD_DEVIATION 13.8 | 47.0 min STANDARD_DEVIATION 16.2 | 50.6 min STANDARD_DEVIATION 18.3 |
| Region of Enrollment Finland | 34 participants | 67 participants | 33 participants |
| Sex: Female, Male Female | 34 Participants | 67 Participants | 33 Participants |
| Sex: Female, Male Male | 0 Participants | 0 Participants | 0 Participants |
| Weight, kg | 80.6 kg STANDARD_DEVIATION 17.2 | 78.2 kg STANDARD_DEVIATION 15.2 | 75.8 kg STANDARD_DEVIATION 12.6 |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — |
| other Total, other adverse events | 1 / 33 | 2 / 34 |
| serious Total, serious adverse events | 0 / 33 | 0 / 34 |
Outcome results
Primary
The Demand of Rescue Analgesics (Oxycodone)
The amount of oxycodone required 48 hours after operation. Oxycodone was administered when the strength of pain is over 3 on numeric rating scale (NRS) 0-10.
Time frame: 48 hours
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Ropivacaine 0,75% | The Demand of Rescue Analgesics (Oxycodone) | 47.5 mg | Standard Deviation 20.9 |
| NaCl 0,9% | The Demand of Rescue Analgesics (Oxycodone) | 57.8 mg | Standard Deviation 29.4 |
Comparison: In a previous non-randomised study at our institution, the mean oxycodone consumption in the control group was 60.7 mg (SD, 22.2 mg) during the first 48 h after caesarean section. At α = 0.05, 31 patients would be needed in each group to achieve a power of 90% for detecting a 30% reduction in the need for rescue opioids, which we considered a clinically meaningful effect. We decided to enrol 70 patients. The final study population was 67 patients.p-value: 0.1t-test, 2 sided
Secondary
Postoperative Nausea and Vomiting (PONV)
The numbers of patients with at least mild nausea at any time post-operatively.
Time frame: 48 hours
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Ropivacaine 0,75% | Postoperative Nausea and Vomiting (PONV) | 7 participants |
| NaCl 0,9% | Postoperative Nausea and Vomiting (PONV) | 11 participants |
p-value: 0.3Chi-squared
Secondary
Strength of Pain on Numerical Rating Scale (NRS)
Intensity of pain was recorded on a numerical rating scale (0-10), where higher scores mean more severe pain, during rest and when moving, for five time intervals (0-6 h, 6-12 h, 12-24 h, 24-36 h and 36-48 h); for each time interval, the highest recorded pain score was taken into account.
Time frame: 48 hours, divided to five time intervals (0-6 h, 6-12 h, 12-24 h, 24-36 h and 36-48 h)
| Arm | Measure | Group | Value (MEDIAN) |
|---|---|---|---|
| Ropivacaine 0,75% | Strength of Pain on Numerical Rating Scale (NRS) | Highest recorded pain scores when moving, 0-6 h | 6.5 units on a scale |
| Ropivacaine 0,75% | Strength of Pain on Numerical Rating Scale (NRS) | Highest recorded pain scores at rest, 0-6 h | 5 units on a scale |
| Ropivacaine 0,75% | Strength of Pain on Numerical Rating Scale (NRS) | Highest recorded pain scores when moving, 6-12 h | 5 units on a scale |
| Ropivacaine 0,75% | Strength of Pain on Numerical Rating Scale (NRS) | Highest recorded pain scores at rest, 24-36 h | 2.25 units on a scale |
| Ropivacaine 0,75% | Strength of Pain on Numerical Rating Scale (NRS) | Highest recorded pain scores when moving, 12-24 h | 5 units on a scale |
| Ropivacaine 0,75% | Strength of Pain on Numerical Rating Scale (NRS) | Highest recorded pain scores at rest, 6-12 h | 3 units on a scale |
| Ropivacaine 0,75% | Strength of Pain on Numerical Rating Scale (NRS) | Highest recorded pain scores when moving, 24-36 h | 4.25 units on a scale |
| Ropivacaine 0,75% | Strength of Pain on Numerical Rating Scale (NRS) | Highest recorded pain scores at rest, 36-48 h | 1 units on a scale |
| Ropivacaine 0,75% | Strength of Pain on Numerical Rating Scale (NRS) | Highest recorded pain scores when moving, 36-48 h | 3 units on a scale |
| Ropivacaine 0,75% | Strength of Pain on Numerical Rating Scale (NRS) | Highest recorded pain scores at rest, 12-24 h | 3 units on a scale |
| NaCl 0,9% | Strength of Pain on Numerical Rating Scale (NRS) | Highest recorded pain scores when moving, 36-48 h | 4 units on a scale |
| NaCl 0,9% | Strength of Pain on Numerical Rating Scale (NRS) | Highest recorded pain scores at rest, 0-6 h | 6 units on a scale |
| NaCl 0,9% | Strength of Pain on Numerical Rating Scale (NRS) | Highest recorded pain scores at rest, 12-24 h | 3 units on a scale |
| NaCl 0,9% | Strength of Pain on Numerical Rating Scale (NRS) | Highest recorded pain scores at rest, 24-36 h | 3 units on a scale |
| NaCl 0,9% | Strength of Pain on Numerical Rating Scale (NRS) | Highest recorded pain scores at rest, 36-48 h | 2 units on a scale |
| NaCl 0,9% | Strength of Pain on Numerical Rating Scale (NRS) | Highest recorded pain scores when moving, 0-6 h | 7 units on a scale |
| NaCl 0,9% | Strength of Pain on Numerical Rating Scale (NRS) | Highest recorded pain scores when moving, 6-12 h | 6 units on a scale |
| NaCl 0,9% | Strength of Pain on Numerical Rating Scale (NRS) | Highest recorded pain scores when moving, 12-24 h | 5.75 units on a scale |
| NaCl 0,9% | Strength of Pain on Numerical Rating Scale (NRS) | Highest recorded pain scores when moving, 24-36 h | 5 units on a scale |
| NaCl 0,9% | Strength of Pain on Numerical Rating Scale (NRS) | Highest recorded pain scores at rest, 6-12 h | 3.75 units on a scale |
Comparison: Highest recorded pain scores at rest, 0-6 hp-value: 0.08Wilcoxon (Mann-Whitney)
Comparison: Highest recorded pain scores at rest, 6-12 hp-value: 0.86Wilcoxon (Mann-Whitney)
Comparison: Highest recorded pain scores at rest, 12-24 hp-value: 0.66Wilcoxon (Mann-Whitney)
Comparison: Highest recorded pain scores at rest, 24-36 hp-value: 0.79Wilcoxon (Mann-Whitney)
Comparison: Highest recorded pain scores at rest, 36-48 hp-value: 0.2Wilcoxon (Mann-Whitney)
Comparison: Highest recorded pain scores when moving, 0-6 hp-value: 0.36Wilcoxon (Mann-Whitney)
Comparison: Highest recorded pain scores when moving, 6-12 hp-value: 0.43Wilcoxon (Mann-Whitney)
Comparison: Highest recorded pain scores when moving, 12-24 hp-value: 0.68Wilcoxon (Mann-Whitney)
Comparison: Highest recorded pain scores when moving, 24-36 hp-value: 0.37Wilcoxon (Mann-Whitney)
Comparison: Highest recorded pain scores when moving, 36-48 hp-value: 0.06Wilcoxon (Mann-Whitney)